The use of effervescence systems in pharmaceutical and detergent tablets is well known to provide effective dissolution of the ingredients of the tablets in water. More recently, effervescence systems have been incorporated in detergent powders to provide improved dissolution.
It is known that effervescence occurs when the effervescence system is in contact with water. Thus, to maximise the effervescence capacity of the system in use, contact with water or moisture should be avoided during manufacturing or storage. Various techniques have been suggested to stabilise the effervescence systems in moist conditions.
For example, in particular pharmaceutical effervescence tablets or powders can be densified by compression or coated, to minimise contact with water or moisture. However, these tablets or powders are often difficult or costly to produce and they do not always result in satisfactory effervescence in use. In particular the dissolution or dispensing of the ingredients of the tablets or powders can be reduced or retarded.
Thus, there is still a need to provide improved effervescence systems for granular or solid detergents, which are stable in moist conditions, readily and inexpensive to produce and which provide excellent dispensing or dissolution of the detergent ingredients.
The inventors now have found that when an effervescence system or component thereof is intimately mixed with specific stabilising material, a very storage stable effervescence particle is obtained, which has a controllable effervescence in use, also resulting in an improved dispensing and dissolution. It is believed that the specific stabilising material reduces the interaction of the effervescence system with moisture. In particularly, effervescence particles having an average particle size of from 75 microns to 2 cm have been found to provide an improved effervescence and storage stability.
The particle may be used in cleaning compositions or cleaning processes. The particle is particularly useful in nonaqueous liquid detergent compositions and solid detergent compositions, including detergent granules, pastilles, flakes and tablets. Thereto, the particle contains preferably one or more detergent actives, which can be (part of) the stabilising agent It has been found that the particle can control the release of these actives. Thus, depending on the exact nature of the particle, the effervescence and the dissolution of the actives can occur immediately upon contact with water, or the start of the effervescence or the dissolution of some of the actives can be delayed, which ever is required. This can result in an improved performance of the actives and an improved cleaning performance of the particle or cleaning composition.
The inventors have furthermore found that when the stabilising particle comprises specific nonionic surfactants, in particular a nonionic polyhydroxy fatty acid amides and/or a nonionic condensation products of aliphatic alcohols, the particle has in use the additional benefit that it provides a very rapid foam formation at the start of the laundry or dish washing process, which is stable during the process.
Furthermore, the inventors have found that incorporation in the effervescent particle of one or more additional cleaning actives, results in a very finely dispersion of the actives in the washing liquor, which improves the dissolution and/or the cleaning performance of these actives. In particular, the inventors have found that the incorporation of a bleaching species and in particular bleach activators, results in an improved bleaching performance and in particular a reduced risk of patchy fabric damage. It is believed that this is due to the improved dispensing and dissolving of the bleaching species or bleach activator, leading to a reduced deposition of these ingredients on the fabric and thus a reduced risk of fabric damage.